a study to assess the safety, tolerability, and pharmacokinetics of giga-2339 in participants with chronic hepatitis b virus infection

Conditions: Hepatitis B Virus Infection

Summary: the primary purpose of this study is to assess the safety and tolerability of single and multiple intravenous (iv) doses of giga-2339 in participants with chronic hepatitis b virus (hbv) infection.


Eligibility criteria:
key inclusion criteria: * hepatitis b envelope antigen (hbeag) negative chronic hbv infection for ≥ 6 months, defined as presence of hepatitis b surface antigen (hbsag) in serum for ≥ 6 months. * serum hbsag concentration between ≥ 100 international units per milliliter (iu/ml) and 2000 iu/ml at screening. * currently on stable dose of nucleot(s)ide analogues (nas) (≥ 6 months) and expected to continue while in study. * serum hbv deoxyribonucleic acid (dna) concentration ≤ 50 iu/ml at screening. * male participants must refrain from donating spermatozoa and agree to use highly effective contraception. * female participants must not be pregnant, or breastfeeding; either should not be a woman of childbearing potential (wocbp) or if wocbp should use highly effective contraceptive methods. key exclusion criteria: * positive for co-infection with hepatitis c virus (hcv), human immunodeficiency virus (hiv), hepatitis d virus (hdv) at screening. * participants that weigh less than 50 kilograms (kg) and/or have a body mass index (bmi) less than 18.5. * history of documented liver cirrhosis at screening. patients under liver cirrhosis evaluation at screening will not be eligible until cirrhosis is ruled out. * liver stiffness \> 8 kilopascal (kpa) at screening. * history of chronic liver disease from another cause, immune complex disease, or autoimmune diseases that in the opinion of the investigator would preclude participation. * family history of hepatocellular carcinoma (hcc). * alpha fetoprotein \> 20 nanograms per milliliter (ng/ml). * presence of a liver imaging reporting and data system (li-rads) 4 or 5 liver lesion on imaging 12 months prior to screening or, li-rads-us findings of us-3 grade on imaging 12 months prior to screening, or lirads-us grade 3 done prior to the d1 infusion visit, if prior li-rads or li-rads-us results are not available at screening. * history of hematopoietic stem cell transplant or solid organ transplant. * receipt of anti-hbv monoclonal antibody (mab) therapy of any kind in the past (including hepatitis b immunoglobulin \[hbig\]). * history of cardiovascular disease (e.g., coronary artery disease, cardiomyopathy, congestive heart failure, family history of congenital long qt syndrome). * malignancy diagnosed and/or treated within 5 years prior to screening, and/or with ongoing treatment for malignancy, with the exception of localized non-metastatic basal cell or squamous cell carcinoma of the skin or in-situ carcinoma of the cervix excised with curative intent. * participants requiring anti-coagulation therapies (for example warfarin, factor xa inhibitors, or anti-platelet agents like clopidogrel). * male participants with a corrected qt interval using fridericia's formula (qtcf) \> 450 milliseconds (msec) and female participants with qtcf \> 470 msec on ecg recorded at screening. participants with evidence of intraventricular conduction delay, defined as qrs interval greater than 110 msec, will be excluded if the qtcf is \> 500 msec for both males and females. * known hypersensitivity to any giga-2339 excipients or any confirmed significant allergic reactions (urticaria or anaphylaxis) against any drug, or multiple drug allergies (nonactive hay fever is acceptable), or a history of drug or other allergy that, in the opinion of the investigator, contraindicates participation. * received or will receive live-attenuated virus vaccinations such as measles, mumps, rubella or varicella within 4 weeks before and up to three months after administration of investigational product (ip).